1. Field of the Invention
This invention relates generally to the field of electrical or fiber-optic connectors possessing moisture and water proof integrity. More specifically, this invention provides enhanced sealing ability of an “O” ring seal adjacent molded plastic parts of the connector.
2. Description of the Prior Art
The terms “male” and “female” designations for electrical connectors are not used consistently in the field. Some connectors are designated as “male” because their inserts are received into the shells of the mating connectors, regardless of whether their electrical contacts are sockets, pins (or blades, etc.), or a combination of sockets and pins. “Insert,” as used herein, designates that part of the connector which holds the contacts in position and electrically insulates them from each other and from the shell. The insert need not be a separate removable component of a connector assembly, as is the case with many cylindrical connector assemblies, and it may include the portion of a bonded unitary connector which performs the same function. The “shell” designates the outside case or outer surface of the connector.
Other connectors (e.g. D-subminiature connectors) are designated as “male”, because their pin contacts are received into the socket contacts of the mating connectors, regardless of the fact that the shells of the male connectors receive the inserts of the female connectors. Furthermore, a connector pair may be arranged with no shell overhang so that neither connector's shell receives the insert of the mating connector. Thus, “male” and “female” designations as used herein are assigned by preference of the inventor for differentiating between complementary connectors in a connector pair. The terms are not meant to be used in any limiting manner.
Other connector gender designations are also used in the electrical connector field, for example the terms “plug” and “receptacle.” As colloquially used, the insert of a “plug” is received into the shell of a “receptacle.” Both plugs and receptacles are known in the art to have pins, sockets or a combination of pins and sockets. However, the “plug” and “receptacle” terminology is also subject to alternative meanings. For instance, “plug” is also defined as a connector which is designed to terminate a free end of a cable or cord, and “receptacle” is defined as a connector which is fixed to a bulkhead, wall, chassis, or panel. In other words, the “plug” is the movable connector and the “receptacle” is the fixed connector, regardless of which insert is received into which shell or which connector has pin contacts, socket contacts, etc. Using the latter terminology, when two cables are joined, the “plug-style” connector is often referred to as a “plug” and the “cable-connecting-receptacle-style connector” is often referred to as a “cable connection plug.” Notwithstanding the above definitions, as used herein, the term “plug” simply refers to that portion of a connector insert which is received into the shell of the other, and the term “receptacle” simply refers to that potion of a connector shell which receives the insert of the other.
When there is a requirement for joining electrical conductors or optical fibers that are to be deployed under water or in humid environments, it is preferable to use connectors that are constructed in such a manner as to offer ease of mating and waterproof integrity. An O-ring, gasket, or packing is typically used to seal the cable end of a connector when repairability or modifiability is a required feature. Alternatively, the connector may be potted, adhesively bonded, or overmolded to create a seal between the cable jacket and the connector if re-entry is not required. However, sealing the interface between two mated connectors has traditionally been limited to the use of gaskets or O-rings which are compressed so that they conform to adjacent surfaces, thereby creating a fluid-proof barrier or seal which can be repeatedly mated and unmated.
The common interface between two connectors is most often sealed by only one sealing element, which is compressively engaged to effect the seal. The sealing element may be a separate and discreet piece which makes up the connector, or it may be an integral part of a unitary molded connector. A connector pair having only one interface sealing element provides no sealing redundancy, so that a defective seal at the connector interface is likely to destroy the integrity of the connection.
A prior art connector pair is shown in FIG. 1 and described in U.S. Pat. No. 7,195,505. FIG. 1 shows a male connector which includes an insert which defines a cylindrical plug with an outer end surface and an outer side surface. The male connector includes one or more electrical or fiber optic contacts such as sockets or pins. The plug of the male connector is characterized by a first annular groove disposed about the outer side surface at a first longitudinal distance from the outer end surface and a first annular compliant sealing element protruding about the outer end surface such that the sealing element is farther from the outer end surface than the groove.
A female connector shown in FIG. 1 includes a shell which defines a receptacle with an inner end surface and an inner side surface. The female connector includes one or more electrical or fiber optic contacts which correspond to the male connector contact for mating purposes. The receptacle of the female connection is characterized by a second annular compliant sealing element protruding about the inner side surface approximately at the first longitudinal distance from the inner end surface and a second annular groove disposed about the inner side surface approximately at the second longitudinal distance from the inner end surface. In other words, the receptacle is arranged and designed to removably receive the plug such that the sealing element of the plug is received in the groove of the receptacle, and vice versa, thereby operably coupling the contacts with redundant seals.
A problem can exist in the sealing capability of the connector where the exterior cylinder surface of the surface of the plug interfaces with the interior cylindrical surface of the insert of the connector of FIG. 1, so that small moisture passages are formed in the connector. This phenomenon is especially a problem when the connector is subjected to high pressure water environments.
3. Identification of Objects of the Invention
A primary object of the invention is to provide a connector that is less likely to be subject to leakage under high pressure water conditions.
Another object of the invention is to provide a soft plastic overmold for a cable to be secured to a male connector where the overmold is designed to surround an insert which is formed of hard molded plastic that has no significant mold parting lines.